Chikungunya virus research. Researcher using a centrifuge to separate Chikungunya virus proteins from cells cultured from Drosophila sp. fruit flies that have been genetically engineered to produce proteins of this virus. The Chikungunya virus (CHIKV) is an insect-borne Alphavirus that is transmitted to humans by virus-carrying Aedes sp. mosquitoes. CHIKV infection causes an illness with symptoms similar to dengue fever, with an acute febrile phase of the illness lasting only two to five days, followed by a prolonged arthralgic disease that affects the joints of the extremities. The pain associated with CHIKV infection of the joints persists for weeks or months, or in some cases years. Photographed at the Pasteur Institute, Paris, France.